1. Field of the Invention
The present invention relates to an exposure apparatus and a method of manufacturing a device using the exposure apparatus.
2. Description of the Related Art
In a process of manufacturing a device, such as an IC or an LSI, a pattern formed on a reticle (which can also be called a photomask or an original) is generally transferred to a substrate, such as a wafer, coated with a photosensitive material (photoresist). An exposure apparatus is used for this transfer. When a foreign particle (foreign substance) adheres on the reticle, or the reticle has a pattern defect, the foreign particle or pattern defect is transferred to the substrate together with the pattern.
To solve this problem, an inspection apparatus inspects the reticle before it is used to expose the substrate to light. The inspection apparatus is built in the exposure apparatus or used as an apparatus outside the exposure apparatus.
In recent years, a method of preparing a reticle having a plurality of pattern regions and transferring only a necessary pattern region to a substrate while shielding regions other than the necessary pattern region from light is often used. A plurality of pattern regions formed on one reticle are used in turn in accordance with, e.g., the progress of a process of manufacturing a semiconductor device. This reticle is often called a multi-layer reticle. In this specification, a reticle having a plurality of pattern regions will be called a multi-pattern reticle, irrespective of whether it is used to manufacture the same device.
Consider a case in which a specific pattern region of a multi-pattern reticle is to be used for the next exposure. In this case, an inspection apparatus inspects all the pattern regions included in a multi-pattern reticle prior to the next exposure. If the multi-pattern reticle is determined to be defective by this inspection and its use is canceled, the throughput lowers. This is because the time taken to inspect pattern regions, other than a pattern region to be used for the next exposure, is wasted.